Interaktion des Belastungskollektives und der Werkzeuggeometrie eines langsamlaufenden Einwellenzerkleinerers

Translated title of the contribution: Interaction of the load collective and the tool geometry of a low-speed single-shaft shredder

Christoph Feyerer

Research output: ThesisMaster's Thesis


Shredding machines - especially low-speed single-shaft shredder - are particularly important for treatment of mixed waste. Because of power reasons they have a big influence on the total cost of ownership of a treatment plant. Furthermore they have direct causes on material quality and they determine the further utilization of the treated waste ressource. Thus, this type of machine is in focus of constant optimization to reduce service costs or to increase product quality regarding subsequent comb-out demands. In the the case of the scientific cooperation partner Komptech GmbH, this is the Terminator series, at which in particular the cutting-tool geometries and the different versions of Shredding-Units are investigated. As main part of this master thesis, a special test setup was designed and utilized for operating measurements as follows. At first, all test machines got equiped with a user-defined torque measurement system. Subsequently, load collectives of specified machine parameters were measured in real operation. A further series of experiments was carried out in which the required tooth forces for breaking through defined specimens got measured. The investigations show that the tooth force required to break through a defined test specimen differs by approximately 60% between the different shredding units. This maximum force dependency between the different shredding units can be recognized in operation under real conditions by the relative frequencies of exceedance of seventy percent of the maximal torque extreme values. These differ by at least 46% between the considered variants. A comparison of efficiency, considering the fuel consumption based on volume throughput, shows that an increase of five percent in material quality of less than 100mm lead to 21% higher specific fuel consumption for shredding unit XXF than variant F. V enables a further five percent increased fraction of the targeted fine material quality, which is expressed in an 111% higher specific fuel consumption, referencing to variant F. That shows that a finer targered material quality has a disproportionate impact on the operating energy requirement. Investigations of different settings of the radial cutting gap show that a larger radial cutting gap leads to an approximately ten percent lower relative frequency of the 70% exceedance extreme values. The reduction in roller speed also reduces this by at least 13%. Moreover, the dependency of influence factors such as torque, speed and material density as statistical values to specific fuel consumption have been studied by self-organizing-maps. A neuronal network was utiliized to estimate the service fuel demands for two shredding unit types. Through the investigations as part of this master thesis, key influencing factors could get identified and their impact could be quantified. This information forms a comprehensive basis for the new and further development of the investigated single–shaft shredder (Terminator). Furthermore the efficiency comparison delivered important information for the overall process engineering and the overall process design of a recycling plant.
Translated title of the contributionInteraction of the load collective and the tool geometry of a low-speed single-shaft shredder
Original languageGerman
Awarding Institution
  • Montanuniversität
  • Leitner, Martin, Co-Supervisor (internal)
  • Stoschka, Michael, Supervisor (internal)
Publication statusPublished - 2020

Bibliographical note

embargoed until 01-03-2025


  • Load collectives
  • Shredding process
  • Single-shaft shredder
  • tool geometry
  • SOM
  • Data analysis

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